Abstract
BACKGROUND:

Genesis of persistent gastro-esophageal reflux symptoms despite proton pump inhibitor (PPI) therapy is not fully understood. We aimed at determining reflux patterns on 24-h pH-impedance monitoring performed on PPI and correlating impedance patterns and symptom occurrence in PPI non-responders.
METHODS:

Seventy-eight PPI non-responder patients underwent 24-h pH-impedance monitoring on PPI. Reflux impedance characterization included gastric and supragastric belches and proximal extent of reflux. Symptoms were considered associated with reflux if occurring within 5 min after a reflux event. Patients were classified into three groups: persistent acid reflux (acid esophageal exposure [AET] >5% of time), reflux sensitivity (AET <5%, symptom index [SI] ≥50%), and functional symptoms (AET <5%, SI <50%). Dominant impedance pattern was determined for each patient.
KEY RESULTS:

Seven patients (9%) had persistent acid reflux, 28 (36%) reflux sensitivity, and 43 (55%) functional symptoms. A total of 4296 reflux events were identified (median per patient 45 [range 4-221]). Although liquid reflux was the most common pattern in all groups, patients with reflux sensitivity and functional symptoms had much more variability in their pattern profile with a large proportion being associated with gastric and supragastric belching. Only 417 reflux events (9.7%) were associated with symptoms. Reflux with a supragastric component and proximal extent were more likely to be associated with symptoms.
CONCLUSIONS & INFERENCES:

The impedance reflux profile in PPI non-responders was heterogeneous and the majority of reflux events were not associated with symptoms. Thus, the treatment of PPI non-responders should focus on mechanisms beyond reflux, such as visceral hypersensitivity and hypervigilance.